autojson 0.1.2

Overview

By defining a Python class, you can define a JSON format. There is no need to define your own JSON parser. You can convert JSON to Python classes with a short code and support the type hints available in vscode’s Pylance extension. Here’s an example of it.

import json
from autojson import Object, Array, Int, Float, Boolean, String

# JSON file
txt = """
{
    "name": "config",
    "threshold": 0.5,
    "flag": true,
    "rectangles": [
        {
            "left": 0,
            "top": 0,
            "width": 100,
            "height": 200
        },
        {
            "left": 100,
            "top": 100,
            "width": 100,
            "height": 200
        }
    ],
    "area": [
        [0, 0],
        [1920, 0],
        [1920, 1080],
        [0, 1080]
    ]
}
"""

# define your JSON format
class Rectangle(Object):
    left = Int()
    top = Int()
    width = Int()
    height = Int()
    right: int
    bottom: int

    def __autojson_init__(self):
        self.right = self.left + self.width
        self.bottom = self.top + self.height

    @property
    def ltwh(self):
        return self.left, self.top, self.width, self.height

    @property
    def ltrb(self):
        return self.left, self.top, self.right, self.bottom


class Config(Object):
    name = String()
    threshold = Float()
    flag = Boolean()
    rectangles = Array(Rectangle())
    area = Array(Array(Int(), size=2))


# load JSON to your class
config = Config().parse_json(json.loads(txt))
# To change parameter
config.threshold = Float(0.7)
# or
config["threshold"] = Float(0.3)

for rectangle in config.rectangles:
    print("ltrb", rectangle.ltrb)
    print("ltwh", rectangle.ltwh)

# if you don't have json template, create the template
print(json.dumps(Config().get_default_json()))
# Object is subclass of dict
# so you can save it as json

Classes

This module provides six classes: Object, Array, Int, Float, Boolean, and String.

Methods

All classes are defined as subclasses of the AutoJson class. Any class that inherits from it will always have two instance methods defined.

Special Methods

__autojson_init__

This is only valid for the Object class. Initialization functions that can be added by the user. It does not accept any arguments, but allows the user to add code that will be executed after being initialized by parse_json. It is used to modify the information read from the file.